Thymic carcinoma patients with myasthenia gravis exhibit better prognoses

Effect of open versus video-assisted thoracoscopy on perioperative outcomes and survival for cases of thymic carcinomas and thymic neuroendocrine tumors

BACKGROUND

The oncology-related indices between open and video-assisted thoracoscopic surgery (VATS) procedures for thymic carcinomas (TCs) and thymic neuroendocrine tumors (TNETs) remain unclear.

METHODS

Propensity score matching (PSM) and multivariate Cox proportional risk models were used to evaluate the perioperative outcomes and survival rates of patients undergoing open and VATS for TCs and TNETs at the Second Affiliated Hospital of Air Force Military Medical University Hospital, between 2009 and 2018.

RESULTS

Of the total 126 cases of TCs and TNETs, VATS treatment was used in 39 (30.9%). Advanced age and Masaoka-Koga staging were found to be independent prognostic factors for both TCs and TNETs, through a multifactorial Cox regression analysis. There was no significant difference in survival between the VATS and open groups before and after PSM; however, the VATS group had better perioperative-related indicators. There were no significant differences between the groups in terms of mortality at 30 days, mortality at 90 days, R0 resection rate, and 5-year survival rate (67.5% vs. 58.5% [P = 0.260] in the VATS group compared to the open group, in a PSM analysis of the 27 VATS and 27 open groups). Compared to the open group, the VATS group had a shorter length of hospital stay (13 days vs. 16 days, P = 0.015), a shorter level I care (0 days vs. 1 day, P = 0.016), and less intraoperative bleeding (50 mL vs. 300 mL, P < 0.001).

CONCLUSIONS

In this single-center retrospective study of TCs and TNETs, survival rates were comparable between the VATS group and the open group, and the VATS group showed improved perioperative-related parameters.

Does Myasthenia Gravis Affect Long-Term Survival in Thymic Carcinomas? An ESTS Database Analysis

Background: Thymic carcinoma is a rare and highly malignant tumor with a dismal prognosis, which occasionally coexists with myasthenia gravis (MG). This study aims to investigate the MG incidence on a surgical cohort of patients with thymic carcinoma and to explore its influence on long-term survival. Methods: the prospectively collected data from the ESTS database on thymic epithelial tumors were reviewed. Clinical, pathological, and survival information on thymic carcinoma were analyzed. Results: the analysis was conducted on 203 patients, with an equal gender distribution (96 males and 107 females). MG was detected in 22 (10.8%) patients, more frequently elderly (>60 years, p = 0.048) and male (p = 0.003). Induction therapy was performed in 22 (10.8%) cases. After surgery, 120 (59.1%) patients had a Masaoka stage II−III while complete resection (R0) was achieved in 158 (77.8%). Adjuvant therapy was performed in 68 cases. Mean follow-up was 60 (SD = 14) months. The 3-year, 5-year and 10-year survival rates were 79%, 75% and 63%, respectively. MG did not seem to influence long-term survival (5-year survival in non-MG−TCs 78% vs. 50% in MG−TCs, p = ns) as age < 60 years, female gender, early Masaoka stage, and postoperative radiotherapy did, conversely. Conclusions: myasthenia occurred in about 10% of thymic carcinomas and it did not seem to affect significantly the long-term prognosis in surgically treated thymic carcinoma-patients.

The Studies of Prognostic Factors and the Genetic Polymorphism of Methylenetetrahydrofolate Reductase C667T in Thymic Epithelial Tumors

Objective

To describe the clinical features of a cohort of patients with thymic epithelial tumors (TETs) and to analyze their prognostic factors. In particular, we investigated the correlation between the genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR) C667T and the incidence of TETs.

Methods

Pathological records were reviewed from the database of the Second Affiliated Hospital of Jiaxing University, from January 2010 to December 2020, and 84 patients with TETs were recruited for this study. Univariate and multivariate analyses were performed to determine the prognostic factors. The genetic polymorphism of MTHFR C667T was examined in the patients with TETs and in a group of healthy individuals. The correlation between MTHFR transcriptional levels and methylation was analyzed using The Cancer Genome Atlas (TCGA) thymoma dataset from the cBioPortal platform.

Results

Kaplan–Meier univariate survival analysis showed that sex, age, the maximum tumor diameter, surgery, chemotherapy, radiotherapy, WHO histological classification, Masaoka–Koga stage, and 8th UICC/AJCC TNM staging, were statistically significantly correlated with the prognosis of patients with TETs. The Masaoka–Koga stage and 8th UICC/AJCC TNM staging were strongly correlated with each other in this study (r=0.925, P<0.001). Cox multivariate survival analysis showed that the maximum tumor diameter, Masaoka–Koga stage, and 8th UICC/AJCC TNM staging were independent prognostic factors affecting the overall survival (OS) of patients with TETs (P<0.05). The MTHFR C667T genotype (χ^{2 =} 7.987, P=0.018) and allele distribution (χ^{2 =} 5.750, P=0.016) were significantly different between the patients and healthy controls. CT heterozygous and TT homozygous genotypes at this MTHFR polymorphism significantly increased the risk of TETs (odds ratio [OR] =4.721, P=0.008). Kaplan–Meier univariate survival analysis showed that there was no correlation between different genotypes and the prognosis of TETs (CC versus CT + TT, χ^{2 =}0.003, P=0.959). Finally, a negative correlation between the transcriptional and methylation levels of MTHFR was observed in the TCGA thymoma dataset (r=-0.24, P=0.010).

Conclusions

The Masaoka–Koga stage, 8th UICC/AJCC TNM staging, and maximum tumor diameter were independent prognostic factors for TETs. Reduced methylation levels of MTHFR and particular polymorphic variants may contribute to the susceptibility to developing TETs.

Thymic Carcinomas-A Concise Multidisciplinary Update on Recent Developments From the Thymic Carcinoma Working Group of the International Thymic Malignancy Interest Group

Thymic carcinomas are rare malignancies that in general arise in the prevascular (anterior) mediastinum. These tumors are usually invasive, often present at advanced stages, and typically behave aggressively. Studies are hampered by the paucity of these tumors, the large variety of carcinoma subtypes, and the lack of unique morphologic and immunophenotypic features. Despite these challenges, advances in diagnostic imaging, surgical approaches, systemic therapies, and radiation therapy techniques have been made. The WHO classification of thymic epithelial tumors has been updated in 2021, and the eighth tumor nodal metastasis staging by the American Joint Committee on Cancer/Union for International Cancer Control included thymic carcinomas in 2017. Molecular alterations that provide more insight into the pathogenesis of these tumors and that potentially permit use of novel targeted therapies are increasingly being identified. New approaches to radiation therapy, chemotherapy, and immunotherapy are under evaluation. International societies, including the International Thymic Malignancy Interest Group, European Society of Thoracic Surgeons, and Japanese, Chinese, and Korean thymic associations, have been critical in organizing and conducting multi-institutional clinical studies. Herein, we review contemporary multidisciplinary perspectives in diagnosis and management of thymic carcinoma.

Thymic Carcinomas and Second Malignancies: A Single-Center Review

Simple Summary

Thymic carcinoma (TC) is a rare neoplasm that accounts for less than 0.01% of all tumors. The aim of our retrospective observational analysis is to review the incidence of second cancers associated with this histological type of cancer. We identified 92 patients with TC referred to our consultation practice and reviewed their clinical data for diagnosis of another cancer pre- or post-diagnosis of TC. This resulted in identification of 14 patients with additional cancers. The incidence of second cancer is similar to that observed in thymomas.

Abstract

Thymic carcinomas account for less than 0.01% of new cancer diagnoses annually and are more aggressive than thymomas. Autoimmune disorders have been associated with thymomas and only recently with thymic carcinomas. Second malignancies are well described after thymomas. The aim of this study was to analyze the incidence of second malignancies in patients with thymic carcinomas. All cases of thymic carcinomas were identified from the pathology archives of Indiana University. Histological materials were reviewed and further correlated with clinical data to identify incidence of second cancers in patients with thymic carcinomas. Histological material was available for review in 92 cases of thymic carcinoma. Clinical data were available for 85 patients. Fourteen of these (16.5%) patients had a second malignancy; these included small cell lung carcinoma, “testicular cancer”, embryonal carcinoma, seminoma, breast carcinoma (two cases), prostatic adenocarcinoma, Hodgkin’s lymphoma, thyroid carcinoma, bladder carcinoma (two cases), renal cell carcinoma, and melanoma. The latter could precede, be concurrent with, or follow the diagnosis thymic carcinoma. The incidence of second cancers in patients with thymic carcinomas is similar to that reported for thymomas. Abnormalities in immunological surveillance may be responsible for this high incidence of second malignancies in thymic tumors.

Myasthenia Gravis Related to Thymic Carcinoma: A Case Study

Myasthenia gravis and thymoma are often presented in association with ∼10% of myasthenic cases having concomitant thymoma. Thymic carcinoma is one of the rarest/aggressive human epithelial tumors and has no correlation with myasthenia gravis hitherto. Here is provided a clinical case and review of literature on a very rare association of thymic carcinoma (with no sign of thymoma) and myasthenia gravis (antiacetylcholine receptor antibody positive). Two years after thymectomy, clinical evolution was satisfactory. This clinical case elicits hypothesis that thymic carcinoma may be related with myasthenia gravis, what may have good prognostic from oncologic and neurologic perspectives.

Role of thymus on prognosis of myasthenia gravis in Turkish population

OBJECTIVE:

Myasthenia gravis (MG) is an autoimmune disease that may cause a disorder in transmission at the neuromuscular junction. Antibodies directed against acetylcholine receptors are responsible. The thymus is the place that that production of these antibodies mainly occurs. The thymus gland abnormalities and abnormal production of these antibodies are associated with MG. Consequently, thymectomy is a common treatment for MG. The nature of the disease makes it difficult to plan prospective, controlled trials; therefore, there is no current consensus among clinicians on a single algorithm of treatment, and the approach is frequently based on the observations and experiences of experts. The contributions to the literature largely consist of retrospective studies examining an approach to treatment and the effects of thymectomy on prognosis. In this retrospective study, evaluation of Turkish patients with myasthenia gravis was carried out for the importance of thymectomy and effects on prognosis.

METHODS:

In this study, 93 patients with myasthenia gravis whose followed up at Neuromuscular outpatient clinic between 1998–2018 were evaluated retrospectively. Type of disease, antibody status, treatment, thymectomy, thymus pathology and prognosis were assessed.

RESULTS:

Thymectomy had been a positive effect on the prognosis of the disease independent of the duration of disease and thymic pathology. The best results had been obtained with early thymectomy with short disease duration, younger age and patients with thymic hyperplasia. Success of therapy was limited with thymoma. With advanced age need for thymectomy was decreased.

CONCLUSION:

In the present study, evaluation of 93 patients with myasthenia gravis was done retrospectively and it was concluded that thymectomy had a positive effect on prognosis, especially in young patients when performed as early as possible. The most successful results were obtained in cases with thymic hyperplasia.

Imaging of extracranial head and neck lesions in cancer patients: a symptom-based approach

Besides intracranial lesions, neurological symptoms are also caused in cancer patients by extracranial lesions in the head and neck. Common symptoms caused by such lesions include visual loss, visual field defect, diplopia, ptosis, sensory abnormalities of the head and neck region, facial nerve palsy, dysphagia, dysarthria, hoarseness, and syncope. Some cancer patients often have multiple cranial nerve involvement, which is associated with several syndromes such as jugular foramen syndrome. The main causes of cranial nerve dysfunction due to extracranial lesions include bone and nodal metastasis, perineural tumor spread, inflammation, and radiation injury. The location of the lesions causing the neurological symptom may be estimated by the symptoms and physical examination. However, CT/MRI is critical for reaching the final diagnosis and for treatment planning and management of the cancer patients. Moreover, early identification of the extracranial lesions may significantly affect patient care and alter outcomes. Thus, radiologists should be familiar with imaging findings of the common neurological disorders and the complex anatomy of the head and neck region, which should be checked in cancer patients with neurological symptoms.

Myasthenia gravis as a prognostic marker in patients with thymoma

Background

Thymoma is the most common mediastinal tumor, representing <1% of all cancers. It is usually associated with paraneoplastic disorders, mainly myasthenia gravis (MG). The aim of the present study was to describe patients with thymoma and the differences between those with MG and those without it.

Methods

A retrospective 10-year database of the patients with thymoma treated at a single cancer referral hospital (National Institute of Cancer, Mexico City), was analyzed.

Results

Sixty-four files from patients with thymoma were analyzed, 18 of them had MG. The symptoms that occurred most frequently in patients with MG were ptosis, diplopia, appendicular weakness, dysphonia and dysphagia. The most frequent Myasthenia Gravis Foundation of America (MGFA) stage was IIIb followed by stage I. Almost all the patients with MG had positive Acetylcholine Receptor antibodies (P<0.001), with not specified antibodies in four patients. The median overall survival showed a trend to be higher among the patients with MG, but there were no significant differences.

Conclusions

In patients with thymoma MG manifests with different clinical and autoimmune traits, but not survival differences. A larger multi-centric study should be encouraged to evaluate the prognostic implications of having MG in patients with thymoma.

Paraneoplastic Syndromes and Thymic Malignancies: An Examination of the International Thymic Malignancy Interest Group Retrospective Database

INTRODUCTION

Thymic epithelial tumors (TETs) are associated with paraneoplastic/autoimmune (PN/AI) syndromes. Myasthenia gravis is the most common PN/AI syndrome associated with TETs.

METHODS

The International Thymic Malignancy Interest Group retrospective database was examined to determine (1) baseline and treatment characteristics associated with PN/AI syndromes and (2) the prognostic role of PN/AI syndromes for patients with TETs. The competing risks model was used to estimate cumulative incidence of recurrence (CIR) and the Kaplan-Meier method was used to calculate overall survival (OS). A Cox proportional hazards model was used for multivariate analysis.

RESULTS

A total of 6670 patients with known PN/AI syndrome status from 1951 to 2012 were identified. PN/AI syndromes were associated with younger age, female sex, thymoma histologic type, earlier stage, and an increased rate of total thymectomy and complete resection status. There was a statistically significant lower CIR in the group with a PN/AI syndrome than in the group without a PN/AI syndrome (10-year CIR 17.3% versus 21.2%, respectively [p = 0.0003]). The OS was improved in the group with a PN/AI syndrome compared to the group without a PN/AI syndrome (median OS 21.6 years versus 17.0 years, respectively [hazard ratio = 0.63, 95% confidence interval: 0.54-0.74, p < 0.0001]). However, in the multivariate model for recurrence-free survival and OS, PN/AI syndrome was not an independent prognostic factor.

DISCUSSION

Previously, there have been mixed data regarding the prognostic role of PN/AI syndromes for patients with TETs. Here, using the largest data set in the world for TETs, PN/AI syndromes were associated with favorable features (i.e., earlier stage and complete resection status) but were not an independent prognostic factor for patients with TETs.

Malignant thymoma with metastasis associated with paraneoplastic myasthenia gravis

We describe a patient who initially presented with a mixed thymic tumor and developed myasthenia gravis 8 years following thymectomy with recurrence of metastatic disease. Metastasis to the pleura, mediastinum, and cervical spine was identified with a positron emission tomography scan when this patient presented with recurring pneumonias and atrial fibrillation. The presentation and diagnosis were clouded by multiple courses of prednisone and chemotherapy for respiratory complications and metastatic disease, respectively. Classical myasthenia gravis symptoms emerged when his prednisone was tapered. The delayed presentation of paraneoplastic disease and the rare metastatic site make this case particularly unusual.

Influence of body mass index on postoperative complications after thymectomy in myasthenia gravis patients

OBJECTIVES

It is not clear whether being overweight or obese influences postoperative complications in myasthenia gravis (MG) patients. We retrospectively investigated an association between body mass index (BMI) and postoperative complications in MG.

MATERIALS AND METHODS

Fifty-nine MG patients who had undergone transsternal thymectomy were classified as low or high BMI based on the criteria for Asian-Pacific populations. An association between BMI and complications was analyzed.

RESULTS

MG patients with high BMI had significantly higher rates of major adverse complications (P = 0.033), postoperative respiratory failure (P = 0.045), and longer postoperative hospitalization (P = 0.005). The optimal cutoff value of BMI for postoperative respiratory failure was 23.3 kg/m2, with a sensitivity of 75.0% and a specificity of 64.7% (P = 0.046).

CONCLUSIONS

MG patients with a BMI indicating overweight or obesity have a higher risk of postoperative complications after thymectomy. Thus, close monitoring must be performed when surgery is necessary.

Rare frequency of gene variation and survival analysis in thymic epithelial tumors

Objective

Thymic epithelial tumor (TET) is a rare mediastinal neoplasm and little is known about its genetic variability and prognostic factors. This study investigated the genetic variability and prognostic factors of TET.

Patients and methods

We sequenced 22 cancer-related hotspot genes in TET tissues and matched normal tissues using Ampliseq Ion Torrent next-generation technology. Overall survival was evaluated using Kaplan–Meier methods and compared with log-rank tests.

Results

A histological analysis of 52 patients with a median age of 52 years showed 15 patients (28.8%) with thymic carcinoma, five with type A thymoma (9.6%), eight with type AB (15.4%), six with type B1 (11.5%), nine with type B2 (17.3%), and nine with type B3 thymoma (17.3%). Three gene mutations were identified, including two with PIK3CA mutation and one with EGFR mutation. The three patients with mutant genes included two cases of thymoma (one with EGFR and the other with PIK3CA mutation) in addition to a case of thymic carcinoma (PIK3CA mutation). The 5-year survival rates were 77.7% in all patients. The 5-year survival rates were 93.3%, 90.0%, 76.9%, and 22.9% corresponding to Masaoka stages I, II, III, and IV (P<0.001). The 5-year survival rates were 100%, 100%, 83.3%, 88.9%, 65.6%, and 60.9% in the histological subtypes of A, AB, B1, B2, and B3 thymomas, and thymic carcinoma, respectively (P=0.012).

Conclusion

Hotspot gene mutations are rare in TET. PIK3CA and EGFR mutations represent candidate driver genes and treatment targets in TET. Masaoka stage and histological subtypes predict the survival of TET.

Response to chemotherapy with carboplatin plus albumin-bound paclitaxel in a patient with lymphoepithelioma-like thymic carcinoma: A case report

Thymic carcinoma is a rare neoplasm with a poor outcome due to its aggressive characteristics. For patients who are not operable, radiation therapy and/or palliative chemotherapy are indicated. However, no optimal chemotherapy regimen has been established. The present study reports the case of a 22-year-old man with advanced lymphoepithelioma-like thymic carcinoma refractory to conventional chemotherapy with carboplatin plus solvent-based paclitaxel (sb-PAC) treatment. The patient was subsequently treated with carboplatin plus nanoparticle albumin-bound paclitaxel (nab-PAC). The treatment resulted in a partial response following three cycles of chemotherapy. Since only grade 3 neutropenia, but no other severe adverse effects, was observed, no dose reduction was required. To the best of our knowledge, the current study is the first to present the response to chemotherapy with carboplatin plus nab-PAC in a patient with lymphoepithelioma-like thymic carcinoma. Considering that no standard treatment has been established in thymic carcinoma, nab-PAC may merit further investigation in this rare, but aggressive disease.